1. Technical Field
The present invention relates to a charger for charging a rechargeable battery. More particularly, this invention relates to a battery charger having a pocket with a battery retention mechanism for securing a battery therein.
2. Background Art
Portable electronic devices are becoming more and more prevalent. Cellular phones, portable radios, pagers, personal organizers, and the like have become mainstays in everyday life. These and other similar devices rely on batteries for their portability. The cost of replacing “single use” batteries, like alkaline batteries for example, can be expensive. In an effort to save consumers money, electronics manufacturers are designing products which incorporate rechargeable batteries instead of single use cells. As rechargeable batteries can be charged and discharged hundreds of times before replacement is needed, the overall cost of operating a rechargeable device becomes much cheaper than using single use cells.
Two-way radios, like those used by police and fire departments, rely heavily upon rechargeable batteries. As lives may be at stake when the policeman or fireman is on the job, it is imperative that their radios have reliable batteries that are consistently ready to perform. For this reason, the battery for each radio is generally charged daily so as to be ready for the next shift.
Prior art chargers 100 for these radios, like that shown in FIG. 1, have included pockets 101 into which either the radio and battery, or the battery alone, may be inserted. Electrical contacts are included in the pocket 101 to charge the battery. The batteries must make a solid electrical connection with the contacts to charge efficiently. If the connection is not sound electrically, a good amount of the charging energy will be lost as heat, thereby unnecessarily extending the charging process. In the worst case, the batteries will not charge at all.
Traditional rechargeable batteries for radios have used nickel cadmium or nickel metal hydride cells, primarily due to their favorable cold weather performance and high discharge capability. Nickel based cells tend to be rather heavy. As such, when a nickel battery is inserted into the pocket of the charger, the sheer weight of the battery is generally sufficient to ensure a reliable electrical connection between the battery and the contacts in the pocket.
New advances in lithium based technologies, however, have made lithium ion and lithium polymer batteries suitable for radio applications. Lithium batteries are quite a bit lighter than are their nickel counterparts. Consequently, when a lithium battery is inserted into a charger pocket, it may not be heavy enough to ensure a proper electrical connection with the contacts. As a result, the charging process may be inefficient and unnecessarily extended.
There is thus a need for a new charger capable of ensuring a proper electrical connection between a lightweight battery and the electrical contacts.